Muscle and bone density is a big differentiator. When I was younger I dated some women who looked very strong. Like, their legs were three times thicker than mine. Yet when it came to actual strength, their legs were a tenth as strong as mine. It was actually kind of shocking how much stronger my legs were than theirs, considering the visual differences. It wasn't until later in life that I learned about the muscle density differences between men and women, and then it made sense. My legs felt like slabs of iron when you touched them. Their legs, despite looking outstanding, still felt fairly soft. That's because of the differences in muscle density between biological males and females.